I'm working with CFHT to develop a citizen-science website, where users would be given a view of a large portion of the sky (an image we provide), and be able to navigate the image similar to google sky and click on certain objects (from a list of coordinates) to find information.

There is also another freebie Celestia. The description reads: "Celestia is an application for real-time 3D visualization of space, with a detailed model of the solar system, over 100,000 stars, more than 10,000 galaxies, and an extension mechanism for adding more objects."